ok guys, i have a major problem with my car (Project-thread) and need some help or idea's. please read the following carefully before posting...!

to make a long story short, tuning my car didn't go as hoped...
i'll try to describe the problems the best i can, hoping you will do some serious thinking with me, seeing that myself and the guys who were tuning my car, don't have any clue on what the hell is going on!

it all starts about 1 year ago when i had some hesitation, and went to my rotary specialist to figure out the problem. it turned out to be a malfunctioning MAF. but in the process of finding the problem we had some hoses changed or unplugged to raise boost. then it hit 0,6bar with no problems or strange noises, we changed it all back to factory boost level. i can remember this: it felt a LOT quicker!

when i started to work on the car last september, the engine was still stock, i had just removed the power steering and A/C, and put on the racingbeat sparkplugs. then i took it for a spin and heard a strange noise coming from the engine and went to check it all out. it sounded like a ticking noise when i hit full boost (stock 0,5bar)
started searching, not knowing what it could be and then i found my fucked up turbo and thought that was it...

last friday i went to a company, who races FC's here in Holland, to get the car tuned.
we started out removing the factory fuel-cut and adjusting fuel @ stock boost (a lower 0,35-0,4bar due to my ported wastegate), no problems there.
all went well and we could be turning up the boost a little.

then all of a sudden, at just 0,5bar, again the same sound! they told me it was detonating like crazy... sounded like someone banging on the floor with a hammer!

we tried many things to figure out where it was coming from, but no luck.
mixture is fine, timing was at zero.
when we advanced the timing a lot, detonation no longer occurred, and we hit 0,9bar.
but then the timing was probably so advanced, that it did not really produce any more power.

they have tried building an engine with non-turbo rotors once and got about the same results.
detonating like crazy on just 0,4-0,5bar
so we compared it to a turboII engine they had, measuring the distance from the plughole to the rotors, they were pretty much the same (a bit hard to measure with the engine in the car) but not that much that it would indicate there would be the wrong rotors in my engine.
that was also almost impossible, due to the fact that i have hit 0,6bar before without any problems.
did a compression test: 6bar on both rotors and all the chambers, which is even a bit on the low side perhaps.

checked the plugs, coils, leads. they all work properly. even put on a stock pair of plugwires instead of the racing beat wires, but with those, the problem was probably even worse!

we decided to stop progress at this point and try to figure out what the problem is before we start spitting out apex seals...! at stock boost there is no problem at all, so i can run it safely for the moment.

so this strange problem was there a long time ago, and all my mods did not affect it and did not make it worse. so it would be safe to say those mods dont have anything to do with it and can be ruled out...

if anyone has any thoughts on this. dont hesitate to let me know!

 

If we eliminate the extreme possibilities, it's going to come down to fuel or ignition timing...

Do you have a fuel pressure gauge?
This will eliminate one possible problem of fuel delivery.

Check ignition timing with a timing gun?
Even revving at idle, you can make sure the timing is advancing properly and not misfiring.
You might want to check that you're not getting an errant spark due to bad plug or wires - run the engine in the dark and see if anything is glowing or sparking in the engine bay.


-Ted

 

yeah i dont want to think about the extremes either at this point
fuel pressure is 2,5-3 at idle, between 4-5bar at full throttle.
plugs (NGK BUR9EQ) and plugwires are brand new, from racing beat, with some stock wires it runs even worse. checked with a light and there were no real abnormalities.
how much should this advance be? and when does it do that exactly?

 

two things come to mind right off the bat, What is the octane in Holland and what temp plugs are you using?

also advancing the timing and getting less detonation is very very strange.

 

I would expect that you would have detonation problems all the time if this was the case but your trailing coils are hooked up to the correct spark plugs right? ie. T1 to the trailing on the front rotor and T2 to the trailing on the rear rotor. I have heard this can cause major detonation problems (and it makes sense it would) and it is possibly a simple mistake.

I guess another thing to think about if you are running an aftermarket ECU; is the coile wired up so that T1 and T2 are the same as stock or could the wires have been crossed?

Just as simple things to start with I guess.

 

octane is 98 (different scale then US) but that is no problem at all.
i am using the stock NGK BUR9EQ's

 

all the wires are connected in the right way
i have the stock ECU, which they have reprogrammed. but i've had the problem before so that's not it.

 

Even though the wires are connected the right way, did you verify with a timing gun too?

To check the timing just revving the engine...
Shoot timing with the timing gun.
Rev engine.
Timing mark should move to the LEFT or counter-clockwise.
The mark should move smoothly - if it's erratic or jumping around, that's bad.
If you can check total advance, measure to see what total advance is.


-Ted

 

What front pulley are you using?

Its possible you may have set the timing in the wrong position due to a misaligned timing mark.

 

checked again today, timing is 0, when revving it goes left for about 35-45degr but did not measure it, so this is what ik can remember.
then after letting of the throttle, it idled higher and the timing had some problems returning to normal, when rpms dropped (lowered idle or releasing clutch a little) the timing would shift back and run normal idle.
so maybe the ECU does not work properly? that it shifts timing too soon or maybe wrong when going into boost?
the guy is going to get me another ECU to try, and then see what happens...

 

stock pulley, and it can only go on in 1 way

 

Yep, but I've seen stock pulleys with different marks that were either made by previous owners, or mixed series wise somewhere down the line.

I would check both trailing plugs with a timing gun, and verify they're toggling correctly and not firing together, or out of phase.

 

Maybe a dumb question, but have you verified that the Crank angle sensor is stabbed correctly?

 

what i forgot to mention, when connecting the single green pin to ground, the CAS is NOT locked like it should be...

timing marks are correct. and the CAS is also in the right way.

 

That could be a function of the modifed ECU....could've had the lock feature disabled when they were mucking with it. Just a thought....

Also refresh my memory since its been a WHILE since I was timing a stock ECU'd car......but shouldn't you HAVE to lock the timing with the green pin in order to verify that the timing is right? As in, when the pin is grounded, it locks the timing to fire the plugs at the timing marks so you know they're firing correctly?

Sorry its been a while for me and stock ECU's.....

 

all problems are solved! turned out to be something fairly easy....

i upped the fuel pressure to 4.5bar at full throttle and replaced the plugs with NGK B9EGV. now there is no more detonation!

in a few weeks i will be updating with new pics, specs and dynosheets!